Field of the Invention
The present invention relates to multihull boats, and more particularly to multihull boats with an extendable platform.
Related Art
There have been many alternative designs that seek to increase the deck space for watercraft on pontoons, including laterally extending decks and longitudinally extending decks. When extending the deck space longitudinally using a ramp, many prior art ramps do not provide any buoyancy to the section of the ramp being extended and others may have negligible buoyancy and slope downward and dip to near water level or at the water level, allowing sections of the deck to be splashed and get wet. Further, such ramps are unstable, particularly in rough weather or choppy water.
The present invention provides an increase in deck space by extending a lower deck longitudinally, while also providing additional longitudinal buoyancy that maintains the elevation of the lower deck above the surface of the water in a near parallel arrangement to the upper deck and avoiding the sloping of the lower deck to water level. The increased buoyancy for the lower deck compensates for the increased structure being supported, which stabilizes the lower deck, even in rough waters. The extended space does not slope toward the water, providing a stable, safe surface to sit, walk or stand.
There are a number of different designs for boats with longitudinally extending decks. As an example of a longitudinally extending deck with a flotation device, U.S. Pat. No. 6,868,799 discloses an extendable ramp with a small cylindrical float located at the end of the ramp. The ramp slopes toward the water and the end of the ramp is essentially level with the water. This patent clearly teaches away from the present invention that provides longitudinal buoyancy to lift the deck and provide stability. As an example of a longitudinally extending deck without any flotation device, U.S. Pat. No. 8,056,496 discloses an extendable deck for a pontoon boat that is stowed under the main deck. The extendable deck has no flotation devices attached, but is levered from the bow of the boat. As the deck is extended beyond its half retracted position, the end of the floating deck begins sloping down and the deck designed to require support by a beach or a boat dock when it is fully extended. This patent likewise teaches away from the claimed invention having longitudinal buoyancy and its resulting stability and safety.
None of the prior art references discloses a secondary deck that is buoyantly supported by pontoons or any other flotation device when the secondary deck is stowed beneath the main deck to which the secondary deck is slidably connected. In addition to providing extra deck space, a secondary deck that has its own buoyant support that is operative when the deck is stowed and when the deck is extended can provide increased stability to the watercraft while maintaining the loading capacity of the watercraft. Known watercraft that merely add slidable planks, ramps or decks which do not offset the weight of these features with an increase in the buoyancy of the watercraft necessarily increase the total weight and therefore reduce the loading capacity of the watercraft. When a float on a ramp is only operable when the ramp is deployed, there is no increase in the buoyancy of the watercraft when the ramp is stowed and this can reduce the stability of the watercraft if the ramp is added to an existing watercraft design. Even if the abeam pontoons are sized larger to accommodate the addition of a ramp, the extension of a ramp that is not supported while it is stowed will necessarily produce a cantilevering effect that will increase the stress on the main deck structure and will also change the boat's attitude in the water while the ramp is cantilevered.
There are also a number of multihull boat designs in which a smaller boat fits between the pontoons or other abeam hull structures of a larger boat, and the smaller boat is secured to the larger boat through various releasable connections. These designs have different configurations and arrangements of the smaller boat and the larger boat, with some smaller boats providing the propulsion for the larger boat while in other cases the larger boat has its own propulsion, and the smaller boat may have propulsion or not In the various alternative designs, the smaller boat may be secured through connections at either the stern or the bow of the larger boat. When the smaller boat is secured at the stern of the larger boat, the larger boat could have a frame, telescoping legs or other structure that extends and retracts in slide retainers or other brackets and releasably connects to the smaller boat, such as disclosed in U.S. Pat. Nos. 3,815,541 and 7,987,803. The smaller boat may maintain its waterline when it is connected to the larger boat, such as in the '803 Patent, or it be partially lifted out of the water, such as in U.S. Pat. Nos. 3,659,546 and 3,815,541, or lifted entirely out of the water, such as in U.S. Pat. App. Pub. No. 2014/0041569. Regardless of the particular configurations and arrangements of such smaller boats secured between the abeam hulls of a larger boat, all of these designs are similar in their use of releasable connections between the smaller and larger boats. The releasable connections between the smaller and larger boats are necessary for launching the smaller boat. Accordingly, although the smaller boat has its own deck and hull apart from the deck of the larger boat, there are no permanent fasteners, stops or other fixed connections that prevent the smaller boat from being deployed because any such connections would defeat the intended purpose of the smaller boat to be launched and separate from the larger boat.
In addition to increasing the extra deck space of a boat, it would also be beneficial to increase the storage space for items that enhance the overall enjoyment of the boat. Known watercraft that merely add slidable planks, ramps or decks certainly improve the functionality of the boat, but these additional features cannot increase the storage space, and they are limited in their usage. The combination of a smaller boat with a larger boat can allow for additional storage space, but the items that can be stowed in the smaller boat are limited if the smaller boat is going to maintain its intended purpose of being launched from the larger boat. Additionally, in order for the storage space in the smaller boat to be usable, it should be readily accessible. Accordingly, the smaller boat does not provide any significant increase in the usable storage space for items that would enhance the overall enjoyment of the boat.